The present invention relates to a variable-volume silo for holding herein unbreakable articles supplied in bulk.
As is known, in a great number of on-line processes performed by processing apparatus operating with different speeds, it is necessary to arrange, between the upstream apparatus and the downstream apparatus, a storing silo for temporarily holding therein pieces or semifinished articles.
A main problem related to the above mentioned holding silos is that of preventing the articles being processes, which are usually fed by gravity, from falling through an excessively large height susceptible to damage or deform said articles.
In order to solve the above mentioned problem, prior apparatus conventionally comprise a flexible belt, made of a cloth material or the like, held inside a box-like body having inner smooth and parallel walls, which, in turn, is provided with an inlet region for feeding the articles into the silo, and an outlet region for unloading downstream said silo the desired articles. The mentioned flexible belt is entrained between the two end portions by a pair of driven rollers for varying the tension and extension of the belt depending on the volume occupied by the articles held in said silo.
Alternately, only one of the end portions of the flexible belt is driven, either for winding or unwinding, by one of the driven rollers.
However, the above approach, while allowing to control the falling height of the articles held in the silo by varying the tension of the flexible belt, does not allow to fully exploit the silo volume.
Thus, it would be necessary to design the silo with a volume greater than that which would be required by the making line, with a consequent increase of the costs.